Full Report
Integer Overflow vulnerability (CVE-2026-53910) has been found in GNU diffutils software.
Analysis Summary
# Vulnerability: Integer Overflow in GNU diffutils diff3 Tool
## CVE Details
- **CVE ID:** CVE-2026-53910
- **CVSS Score:** Not explicitly rated in the report (Estimated High based on RCE potential)
- **CWE:** CWE-190 (Integer Overflow or Wraparound)
## Affected Systems
- **Products:** GNU diffutils (specifically the `diff3` utility)
- **Versions:** All versions through 3.12
- **Configurations:** Systems where `diff3` is used to process untrusted diff output or where the `--diff-program` argument can be influenced by an attacker.
## Vulnerability Description
The `diff3` tool in GNU diffutils contains multiple signed integer overflows within its line-mapping calculations. When the tool processes input, incorrect arithmetic in mapping line ranges leads to corrupted values. These corrupted values are subsequently used for memory allocation and loop bounds.
Specifically, these overflows cause the application to allocate an insufficient amount of memory on the heap. During internal processing, the application then performs out-of-bounds writes into that undersized buffer.
## Exploitation
- **Status:** PoC status not explicitly confirmed, but technical details suggest a report-driven discovery.
- **Complexity:** Medium (Requires controlling the diff output/program input).
- **Attack Vector:** Local (Triggered via processing of crafted diff files or use of the `--diff-program` flag).
## Impact
- **Confidentiality:** High (Potential for memory leakage or arbitrary code execution).
- **Integrity:** High (Memory corruption and potential for remote code execution).
- **Availability:** High (Results in application crash/DoS).
## Remediation
### Patches
- The vulnerability has been addressed in the GNU diffutils source.
- **Fix Commit:** `9ff04d5b84743e331e80b589335a52c5480d1815`
- Users are advised to upgrade to versions released after 3.12 or apply the patch provided by their distribution maintainer.
### Workarounds
- Avoid using the `--diff-program` argument with untrusted or unverified scripts.
- Restrict the processing of diff files from untrusted sources until the software is patched.
## Detection
- **Indicators of Compromise:** Unexpected crashes (SIGSEGV) of the `diff3` process when handling specific files.
- **Detection methods and tools:** Memory sanitizers (e.g., ASAN) can be used during testing to identify line-mapping arithmetic errors and heap overflows.
## References
- **Vendor Advisory:** [https[:]//cert[.]pl/en/posts/2026/07/vulnerability-in-gnu-diffutils/](https[:]//cert[.]pl/en/posts/2026/07/vulnerability-in-gnu-diffutils/)
- **CVE Record:** [https[:]//www[.]cve[.]org/CVERecord?id=CVE-2026-53910](https[:]//www[.]cve[.]org/CVERecord?id=CVE-2026-53910)
- **CVD Policy:** [https[:]//cert[.]pl/en/cvd](https[:]//cert[.]pl/en/cvd)